The invention relates generally to apparatuses for removing particulates from objects and deals more particularly with apparatuses which remove particulates from gloved hands, clad feet, wipes and other objects by use of an air stream, and prevents the removed particulates from re-entering the surrounding environment.
Apparatuses of the general type with which this invention is concerned are used in conjunction with clean rooms such as semiconductor and pharmaceutical fabrication rooms, hospital operating rooms, certain laboratories any other rooms where it is important to provide an environment which is very low in particulates such as dirt, dust, skin cells and bacteria. In such rooms, workers often wear gloves and booties to prevent such particulates on their hands and feet from contaminating objects which the worker touches and to prevent such particulates from being shaken into the air from their hands and feet and randomly contaminating other objects in the room.
A worker often begins a work day with a relatively clean pair of gloves and booties which he or she removes directly from sealed packages in a clean room. However, in removing the gloves and booties, some particulates from within the packages escape into the clean room and in donning the gloves and booties, the worker invariably touches exterior surfaces of them with his or her hands and thereby contaminates such exterior surfaces. Also, during the course of a workday, the worker often touches his or her hands to exposed portions of his or her face and to other relatively dirty objects and thereby, contaminates the gloves further, and often brushes his or her feet against dirty furniture and steps on dirty portions of the floor and thereby contaminates the booties further.
Presently, it is common for workers to change their gloves and booties during the course of a workday and discard the contaminated, old ones. Also, there are air showers located adjacent or within some clean rooms to clean particulates from a person, which air showers typically comprise a small enclosed shower room having an entrance door and an exit door, and blowers which produce air streams within the shower room. The blowers force air through apertures in the walls and ceilings of the shower room and return the air through other apertures usually in the floor. High efficiency air particulate (HEPA) filters are also provided to cleanse the air returned from the shower room, such filters being effective in trapping particulates 0.3 microns in diameter and larger.
The apertures in one type of shower room take the form of a pair of coplanar slots located in opposing walls, and extending vertically from a point a few feet high to a point approximately five feet high. To correctly utilize this type of air shower, a worker opens the entrance door, enters the shower room, positions himself or herself between the slots, raises his or her arms and turns in a complete circle. The blower forces a stream of generally laminar air through each slot, into the shower room and against the person to dislodge particles from the person's body. Some of the particulates are immediately entrained in the return flow of air and drawn through the floor and the filter, and other of the dislodged particulates float into the air within the shower room, are contained by the walls and ceiling of the shower room and most are eventually entrained in the return flow of air and filtered. However, some of these other particulates may escape from the shower room when the worker exits.
Another similar type of air shower uses a group of nozzles located on the ceiling and walls of the associated shower room instead of the vertical slots to direct streams of air against a user.
Air showers of the types described above are general purpose apparatuses for cleaning one's body and do not concentrate on the hands and feet which, as discussed above, are particular sources of repeated contamination. Also, the shower rooms take up many square feet of floor space and the process of utilizing the air showers, from the time the user opens the entrance door to the time the worker exits the shower room, usually requires 30 seconds or more and is inconvenient. Furthermore, the doors of the type of air shower room discussed above are opened manually with handles, which handles provide a source of contamination.
Cleaning and heat-shrinking apparatuses for thermoplastic gloves are presently known which comprise a blower, a high-efficiency particulate filter located between the blower and the object to be cleaned, and a heater to heat the blown air before it reaches the object. The hot air shrinks gloves worn by a user to improve their fit, trap particulates, and dislodge particulates from the gloves. However, the air blown by the blower is not recirculated and no air curtain is provided to block the dislodged particulates so that the dislodged particulates enter the surrounding environment. Consequently, such a device is usually installed outside of a clean room.
There are other objects used in clean rooms which are contaminated with particulates and require cleaning, for example, parts used to fabricate a product and wipes used to clean furniture, equipment and such fabrication parts. Presently, the wipes are discarded after use.
Accordingly, a general aim of the invention is to provide a cleaning apparatus which effectively removes particulates from objects such as gloved hands, clad feet, wipes and fabrication parts and prevents the particulates from re-entering a workroom.
Another general aim of the invention is to provide a cleaning apparatus of the foregoing type which removes the particulates quickly with minimal inconvenience to the user.
A more specific aim of the invention is to provide apparatuses of the foregoing types which are more compact than a conventional air shower and concentrate their cleaning efforts on objects which are small compared to a worker's entire body.
Another specific aim of the invention is to provide cleaning apparatuses of the foregoing types which remove particulates 0.3 microns in diameter and larger.
Still another specific aim of the invention is to provide a cleaning system which is specially adapted to remove particulates from large quantities of wipes.
Other aims of the invention will become apparent from the following detailed descriptions and drawings.